Bonzi PGR Plant Growth Regulator | Paclobutrazol PGR
Bonzi PGR controls stretch in ornamentals with 0.4% paclobutrazol for compact, uniform greenhouse and nursery crops.
Bonzi PGR Plant Growth Regulator helps professional growers produce compact, attractive ornamental plants with more consistent height and shape. It is especially useful in greenhouse and nursery production where uncontrolled stretch can affect spacing, appearance, shipping, and retail quality.
Powered by paclobutrazol, Bonzi works within the plant to slow excessive stem elongation. The result is a shorter, sturdier, more balanced crop that is easier to manage through the production cycle. Growers can apply Bonzi as a foliar spray, media drench, or bulb soak depending on the crop and desired level of growth control.
Bonzi is a strong fit for bedding plants, plugs, flowering pot crops, bulb crops, foliage plants, and container-grown woody ornamentals. Whether used early to guide plant structure or later to help prevent stretch before sale, Bonzi gives growers a practical way to maintain crop quality and improve finished plant presentation.
Bonzi PGR Plant Growth Regulator is a professional ornamental growth regulator designed to help greenhouse and nursery growers manage plant height, reduce unwanted stretch, and produce compact, uniform, retail-ready crops. Formulated with 0.4% paclobutrazol, Bonzi works systemically to reduce internode elongation by interfering with gibberellin biosynthesis, helping plants develop a tighter, more balanced appearance. The uploaded product label lists Bonzi as an aqueous solution containing 0.12 gram active ingredient per fluid ounce, equal to 4,000 ppm.
Bonzi is labeled for ornamental plants grown in containers in nurseries, greenhouses, shadehouses, and interiorscapes. It is widely used on bedding plants, plugs, flowering and foliage plants, bulb crops, pot chrysanthemums, poinsettias, geraniums, hibiscus, azaleas, and container-grown woody ornamentals when applied according to label directions. Syngenta’s GreenCast product information also identifies paclobutrazol as the active ingredient and EPA Reg. No. 100-996.
Product Snapshot
| Product Feature |
Details |
| Product Name |
Bonzi PGR Plant Growth Regulator |
| Product Type |
Ornamental plant growth regulator |
| Active Ingredient |
Paclobutrazol |
| Concentration |
0.4% paclobutrazol |
| Formulation |
Aqueous solution |
| Active Ingredient Strength |
4,000 ppm / 0.12 g ai per fl oz |
| EPA Registration |
EPA Reg. No. 100-996 |
| Primary Use |
Controls excessive height and internode stretch in ornamental crops |
| Labeled Production Sites |
Greenhouses, nurseries, shadehouses, interiorscapes, container ornamental production |
| Main Application Types |
Spray, drench, and pre-plant bulb soak |
Key Benefits of Bonzi Plant Growth Regulator
| Grower Challenge |
How Bonzi Helps |
| Excessive stem stretch |
Reduces internode elongation for shorter, more compact plants |
| Uneven crop height |
Supports improved crop uniformity when applied consistently |
| Overly vigorous vegetative growth |
Helps balance plant structure and finished size |
| Weak retail presentation |
Produces a tighter, more professional plant-to-pot ratio |
| Shipping and handling concerns |
Compact plants are easier to space, move, and merchandise |
| Late-season height control |
Drench applications can provide longer-lasting and more uniform control than sprays when label-directed |
| Labor-intensive trimming |
Helps reduce the need for corrective pruning and height management |
How Bonzi PGR Works
Bonzi is powered by paclobutrazol, a triazole plant growth regulator that reduces plant height by inhibiting gibberellin synthesis, a plant hormone pathway associated with cell elongation and internode extension. Research on paclobutrazol explains that when gibberellin production is reduced, shoots form with compressed internodes, resulting in shorter, more compact growth.
Because Bonzi can be absorbed through treated plant tissue and roots, growers can choose application methods based on crop type, growth stage, production schedule, and desired level of height control. The label identifies spray applications, drench applications, and pre-plant bulb soaks as the primary methods for achieving height control.
Labeled Application Overview
| Application Method |
Best-Fit Use |
| Foliar Spray |
Useful for controlling stem elongation when thorough stem coverage is needed |
| Soil / Media Drench |
Provides strong, uniform, and longer-lasting height control when applied to moist growing media |
| Pre-Plant Bulb Soak |
Used for labeled bulb crops where height control is needed before planting |
| Chemigation / Irrigation Delivery |
Permitted only through label-specified systems and with required calibration and safety measures |
Ideal Crops and Use Areas
Bonzi PGR is a strong fit for commercial ornamental programs where consistent height, compact form, and finished crop quality are important.
| Crop Category |
Examples |
| Bedding Plants |
Ageratum, celosia, coleus, dahlia, dianthus, impatiens, marigold, pansy, petunia, salvia, snapdragon, verbena, zinnia |
| Plugs |
Bedding plant plugs where low-rate, carefully timed spray programs are appropriate |
| Flowering Pot Crops |
Poinsettias, chrysanthemums, hibiscus, geraniums, azaleas |
| Bulb Crops |
Tulip, hybrid lily, calla lily, caladium, amaryllis and other labeled bulb crops |
| Woody Ornamentals |
Azalea, bougainvillea, camellia, hydrangea, holly, juniper, magnolia, photinia, rhododendron and other labeled container ornamentals |
| Production Sites |
Greenhouses, nurseries, shadehouses, interiorscapes, and container ornamental production areas |
Professional Growing Advantages
Bonzi PGR helps growers produce plants with a compact, premium finish that meets modern retail and shipping expectations. By controlling excessive shoot elongation, Bonzi supports more predictable spacing, improved crop consistency, and a more attractive finished appearance. For high-density greenhouse production, this can help growers maintain better bench efficiency while reducing the risk of overgrown, uneven, or difficult-to-ship crops.
Drench applications are especially useful when crops are near the desired market size because the label notes that media applications can provide longer-lasting and more uniform control than spray applications, with little effect on flower size when used as directed.
Important Label and Safety Note
Always read and follow the current EPA-approved product label before use. Application rates vary by crop, cultivar vigor, pot size, growing media, temperature, geography, timing, and desired level of control. The label advises small-scale trials before treating large numbers of plants and states not to exceed maximum recommended rates. The EPA has a product label record for Bonzi Ornamental Growth Regulator under EPA Registration No. 100-996.
Active ingredient: 0.4% Paclobutrazol
Product Label
